DE 82 17 700 U1 discloses a specimen head, displaceable in two spatial directions, that is enclosed by a bracket. Displacement of the bracket is accomplished via two link elements arranged one above another and shiftable with respect to one another. Two spindles arranged parallel to one another, each having a sliding block, are in working engagement with the link elements. One of the sliding blocks is connected via a lever mechanism to the first link element. The second sliding block engages into an elongated hole, arranged obliquely with respect to the spindle axis, of the second link element. An indication for the zero position of the specimen head is not provided here.
DE 196 04 001 C2 discloses a device for orienting a specimen head in a microtome. In this microtome, the specimen head is immovably connected to a ball joint for orientation. The ball joint has a ball, arranged between two ball half-shells, that is connected, for separate X-Y orientation of the specimen head, to a universal joint arranged inside the two ball half-shells. The universal joint has two handles, arranged perpendicular to one another, each having a threaded spindle. The threaded spindles are mounted rotatably in the ball half-shell and are each equipped with a nut. The nuts are each immovably connected to a pin, and the pins engage into two elongated holes, arranged perpendicular to one another, of the universal joint. A rotational motion at the handles is transferred via the threaded spindles to the nuts and the pins. The longitudinal motion of a pin is transferred to the universal joint, so that the specimen holder is pivoted or tilted in the spatial direction.
This device has proven successful in practical use, but is not equipped with any indication for recognition of the zero position of the specimen holder. As a result of the very small maximum pivot angle (≦8°), however, it is sometimes very difficult to align the sample accurately onto the cutting knife and to recognize the zero position, i.e. the location between two end positions of the nut.